1 #ifndef _LINUX_SIGNAL_H 2 #define _LINUX_SIGNAL_H 3 4 #include <linux/list.h> 5 #include <linux/bug.h> 6 #include <uapi/linux/signal.h> 7 8 struct task_struct; 9 10 /* for sysctl */ 11 extern int print_fatal_signals; 12 /* 13 * Real Time signals may be queued. 14 */ 15 16 struct sigqueue { 17 struct list_head list; 18 int flags; 19 siginfo_t info; 20 struct user_struct *user; 21 }; 22 23 /* flags values. */ 24 #define SIGQUEUE_PREALLOC 1 25 26 struct sigpending { 27 struct list_head list; 28 sigset_t signal; 29 }; 30 31 /* 32 * Define some primitives to manipulate sigset_t. 33 */ 34 35 #ifndef __HAVE_ARCH_SIG_BITOPS 36 #include <linux/bitops.h> 37 38 /* We don't use <linux/bitops.h> for these because there is no need to 39 be atomic. */ 40 static inline void sigaddset(sigset_t *set, int _sig) 41 { 42 unsigned long sig = _sig - 1; 43 if (_NSIG_WORDS == 1) 44 set->sig[0] |= 1UL << sig; 45 else 46 set->sig[sig / _NSIG_BPW] |= 1UL << (sig % _NSIG_BPW); 47 } 48 49 static inline void sigdelset(sigset_t *set, int _sig) 50 { 51 unsigned long sig = _sig - 1; 52 if (_NSIG_WORDS == 1) 53 set->sig[0] &= ~(1UL << sig); 54 else 55 set->sig[sig / _NSIG_BPW] &= ~(1UL << (sig % _NSIG_BPW)); 56 } 57 58 static inline int sigismember(sigset_t *set, int _sig) 59 { 60 unsigned long sig = _sig - 1; 61 if (_NSIG_WORDS == 1) 62 return 1 & (set->sig[0] >> sig); 63 else 64 return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW)); 65 } 66 67 #endif /* __HAVE_ARCH_SIG_BITOPS */ 68 69 static inline int sigisemptyset(sigset_t *set) 70 { 71 switch (_NSIG_WORDS) { 72 case 4: 73 return (set->sig[3] | set->sig[2] | 74 set->sig[1] | set->sig[0]) == 0; 75 case 2: 76 return (set->sig[1] | set->sig[0]) == 0; 77 case 1: 78 return set->sig[0] == 0; 79 default: 80 BUILD_BUG(); 81 return 0; 82 } 83 } 84 85 #define sigmask(sig) (1UL << ((sig) - 1)) 86 87 #ifndef __HAVE_ARCH_SIG_SETOPS 88 #include <linux/string.h> 89 90 #define _SIG_SET_BINOP(name, op) \ 91 static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \ 92 { \ 93 unsigned long a0, a1, a2, a3, b0, b1, b2, b3; \ 94 \ 95 switch (_NSIG_WORDS) { \ 96 case 4: \ 97 a3 = a->sig[3]; a2 = a->sig[2]; \ 98 b3 = b->sig[3]; b2 = b->sig[2]; \ 99 r->sig[3] = op(a3, b3); \ 100 r->sig[2] = op(a2, b2); \ 101 case 2: \ 102 a1 = a->sig[1]; b1 = b->sig[1]; \ 103 r->sig[1] = op(a1, b1); \ 104 case 1: \ 105 a0 = a->sig[0]; b0 = b->sig[0]; \ 106 r->sig[0] = op(a0, b0); \ 107 break; \ 108 default: \ 109 BUILD_BUG(); \ 110 } \ 111 } 112 113 #define _sig_or(x,y) ((x) | (y)) 114 _SIG_SET_BINOP(sigorsets, _sig_or) 115 116 #define _sig_and(x,y) ((x) & (y)) 117 _SIG_SET_BINOP(sigandsets, _sig_and) 118 119 #define _sig_andn(x,y) ((x) & ~(y)) 120 _SIG_SET_BINOP(sigandnsets, _sig_andn) 121 122 #undef _SIG_SET_BINOP 123 #undef _sig_or 124 #undef _sig_and 125 #undef _sig_andn 126 127 #define _SIG_SET_OP(name, op) \ 128 static inline void name(sigset_t *set) \ 129 { \ 130 switch (_NSIG_WORDS) { \ 131 case 4: set->sig[3] = op(set->sig[3]); \ 132 set->sig[2] = op(set->sig[2]); \ 133 case 2: set->sig[1] = op(set->sig[1]); \ 134 case 1: set->sig[0] = op(set->sig[0]); \ 135 break; \ 136 default: \ 137 BUILD_BUG(); \ 138 } \ 139 } 140 141 #define _sig_not(x) (~(x)) 142 _SIG_SET_OP(signotset, _sig_not) 143 144 #undef _SIG_SET_OP 145 #undef _sig_not 146 147 static inline void sigemptyset(sigset_t *set) 148 { 149 switch (_NSIG_WORDS) { 150 default: 151 memset(set, 0, sizeof(sigset_t)); 152 break; 153 case 2: set->sig[1] = 0; 154 case 1: set->sig[0] = 0; 155 break; 156 } 157 } 158 159 static inline void sigfillset(sigset_t *set) 160 { 161 switch (_NSIG_WORDS) { 162 default: 163 memset(set, -1, sizeof(sigset_t)); 164 break; 165 case 2: set->sig[1] = -1; 166 case 1: set->sig[0] = -1; 167 break; 168 } 169 } 170 171 /* Some extensions for manipulating the low 32 signals in particular. */ 172 173 static inline void sigaddsetmask(sigset_t *set, unsigned long mask) 174 { 175 set->sig[0] |= mask; 176 } 177 178 static inline void sigdelsetmask(sigset_t *set, unsigned long mask) 179 { 180 set->sig[0] &= ~mask; 181 } 182 183 static inline int sigtestsetmask(sigset_t *set, unsigned long mask) 184 { 185 return (set->sig[0] & mask) != 0; 186 } 187 188 static inline void siginitset(sigset_t *set, unsigned long mask) 189 { 190 set->sig[0] = mask; 191 switch (_NSIG_WORDS) { 192 default: 193 memset(&set->sig[1], 0, sizeof(long)*(_NSIG_WORDS-1)); 194 break; 195 case 2: set->sig[1] = 0; 196 case 1: ; 197 } 198 } 199 200 static inline void siginitsetinv(sigset_t *set, unsigned long mask) 201 { 202 set->sig[0] = ~mask; 203 switch (_NSIG_WORDS) { 204 default: 205 memset(&set->sig[1], -1, sizeof(long)*(_NSIG_WORDS-1)); 206 break; 207 case 2: set->sig[1] = -1; 208 case 1: ; 209 } 210 } 211 212 #endif /* __HAVE_ARCH_SIG_SETOPS */ 213 214 static inline void init_sigpending(struct sigpending *sig) 215 { 216 sigemptyset(&sig->signal); 217 INIT_LIST_HEAD(&sig->list); 218 } 219 220 extern void flush_sigqueue(struct sigpending *queue); 221 222 /* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */ 223 static inline int valid_signal(unsigned long sig) 224 { 225 return sig <= _NSIG ? 1 : 0; 226 } 227 228 struct timespec; 229 struct pt_regs; 230 231 extern int next_signal(struct sigpending *pending, sigset_t *mask); 232 extern int do_send_sig_info(int sig, struct siginfo *info, 233 struct task_struct *p, bool group); 234 extern int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p); 235 extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *); 236 extern int do_sigtimedwait(const sigset_t *, siginfo_t *, 237 const struct timespec *); 238 extern int sigprocmask(int, sigset_t *, sigset_t *); 239 extern void set_current_blocked(sigset_t *); 240 extern void __set_current_blocked(const sigset_t *); 241 extern int show_unhandled_signals; 242 243 struct sigaction { 244 #ifndef __ARCH_HAS_IRIX_SIGACTION 245 __sighandler_t sa_handler; 246 unsigned long sa_flags; 247 #else 248 unsigned int sa_flags; 249 __sighandler_t sa_handler; 250 #endif 251 #ifdef __ARCH_HAS_SA_RESTORER 252 __sigrestore_t sa_restorer; 253 #endif 254 sigset_t sa_mask; /* mask last for extensibility */ 255 }; 256 257 struct k_sigaction { 258 struct sigaction sa; 259 #ifdef __ARCH_HAS_KA_RESTORER 260 __sigrestore_t ka_restorer; 261 #endif 262 }; 263 264 #ifdef CONFIG_OLD_SIGACTION 265 struct old_sigaction { 266 __sighandler_t sa_handler; 267 old_sigset_t sa_mask; 268 unsigned long sa_flags; 269 __sigrestore_t sa_restorer; 270 }; 271 #endif 272 273 struct ksignal { 274 struct k_sigaction ka; 275 siginfo_t info; 276 int sig; 277 }; 278 279 extern int get_signal(struct ksignal *ksig); 280 extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping); 281 extern void exit_signals(struct task_struct *tsk); 282 extern void kernel_sigaction(int, __sighandler_t); 283 284 static inline void allow_signal(int sig) 285 { 286 /* 287 * Kernel threads handle their own signals. Let the signal code 288 * know it'll be handled, so that they don't get converted to 289 * SIGKILL or just silently dropped. 290 */ 291 kernel_sigaction(sig, (__force __sighandler_t)2); 292 } 293 294 static inline void disallow_signal(int sig) 295 { 296 kernel_sigaction(sig, SIG_IGN); 297 } 298 299 extern struct kmem_cache *sighand_cachep; 300 301 int unhandled_signal(struct task_struct *tsk, int sig); 302 303 /* 304 * In POSIX a signal is sent either to a specific thread (Linux task) 305 * or to the process as a whole (Linux thread group). How the signal 306 * is sent determines whether it's to one thread or the whole group, 307 * which determines which signal mask(s) are involved in blocking it 308 * from being delivered until later. When the signal is delivered, 309 * either it's caught or ignored by a user handler or it has a default 310 * effect that applies to the whole thread group (POSIX process). 311 * 312 * The possible effects an unblocked signal set to SIG_DFL can have are: 313 * ignore - Nothing Happens 314 * terminate - kill the process, i.e. all threads in the group, 315 * similar to exit_group. The group leader (only) reports 316 * WIFSIGNALED status to its parent. 317 * coredump - write a core dump file describing all threads using 318 * the same mm and then kill all those threads 319 * stop - stop all the threads in the group, i.e. TASK_STOPPED state 320 * 321 * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored. 322 * Other signals when not blocked and set to SIG_DFL behaves as follows. 323 * The job control signals also have other special effects. 324 * 325 * +--------------------+------------------+ 326 * | POSIX signal | default action | 327 * +--------------------+------------------+ 328 * | SIGHUP | terminate | 329 * | SIGINT | terminate | 330 * | SIGQUIT | coredump | 331 * | SIGILL | coredump | 332 * | SIGTRAP | coredump | 333 * | SIGABRT/SIGIOT | coredump | 334 * | SIGBUS | coredump | 335 * | SIGFPE | coredump | 336 * | SIGKILL | terminate(+) | 337 * | SIGUSR1 | terminate | 338 * | SIGSEGV | coredump | 339 * | SIGUSR2 | terminate | 340 * | SIGPIPE | terminate | 341 * | SIGALRM | terminate | 342 * | SIGTERM | terminate | 343 * | SIGCHLD | ignore | 344 * | SIGCONT | ignore(*) | 345 * | SIGSTOP | stop(*)(+) | 346 * | SIGTSTP | stop(*) | 347 * | SIGTTIN | stop(*) | 348 * | SIGTTOU | stop(*) | 349 * | SIGURG | ignore | 350 * | SIGXCPU | coredump | 351 * | SIGXFSZ | coredump | 352 * | SIGVTALRM | terminate | 353 * | SIGPROF | terminate | 354 * | SIGPOLL/SIGIO | terminate | 355 * | SIGSYS/SIGUNUSED | coredump | 356 * | SIGSTKFLT | terminate | 357 * | SIGWINCH | ignore | 358 * | SIGPWR | terminate | 359 * | SIGRTMIN-SIGRTMAX | terminate | 360 * +--------------------+------------------+ 361 * | non-POSIX signal | default action | 362 * +--------------------+------------------+ 363 * | SIGEMT | coredump | 364 * +--------------------+------------------+ 365 * 366 * (+) For SIGKILL and SIGSTOP the action is "always", not just "default". 367 * (*) Special job control effects: 368 * When SIGCONT is sent, it resumes the process (all threads in the group) 369 * from TASK_STOPPED state and also clears any pending/queued stop signals 370 * (any of those marked with "stop(*)"). This happens regardless of blocking, 371 * catching, or ignoring SIGCONT. When any stop signal is sent, it clears 372 * any pending/queued SIGCONT signals; this happens regardless of blocking, 373 * catching, or ignored the stop signal, though (except for SIGSTOP) the 374 * default action of stopping the process may happen later or never. 375 */ 376 377 #ifdef SIGEMT 378 #define SIGEMT_MASK rt_sigmask(SIGEMT) 379 #else 380 #define SIGEMT_MASK 0 381 #endif 382 383 #if SIGRTMIN > BITS_PER_LONG 384 #define rt_sigmask(sig) (1ULL << ((sig)-1)) 385 #else 386 #define rt_sigmask(sig) sigmask(sig) 387 #endif 388 #define siginmask(sig, mask) (rt_sigmask(sig) & (mask)) 389 390 #define SIG_KERNEL_ONLY_MASK (\ 391 rt_sigmask(SIGKILL) | rt_sigmask(SIGSTOP)) 392 393 #define SIG_KERNEL_STOP_MASK (\ 394 rt_sigmask(SIGSTOP) | rt_sigmask(SIGTSTP) | \ 395 rt_sigmask(SIGTTIN) | rt_sigmask(SIGTTOU) ) 396 397 #define SIG_KERNEL_COREDUMP_MASK (\ 398 rt_sigmask(SIGQUIT) | rt_sigmask(SIGILL) | \ 399 rt_sigmask(SIGTRAP) | rt_sigmask(SIGABRT) | \ 400 rt_sigmask(SIGFPE) | rt_sigmask(SIGSEGV) | \ 401 rt_sigmask(SIGBUS) | rt_sigmask(SIGSYS) | \ 402 rt_sigmask(SIGXCPU) | rt_sigmask(SIGXFSZ) | \ 403 SIGEMT_MASK ) 404 405 #define SIG_KERNEL_IGNORE_MASK (\ 406 rt_sigmask(SIGCONT) | rt_sigmask(SIGCHLD) | \ 407 rt_sigmask(SIGWINCH) | rt_sigmask(SIGURG) ) 408 409 #define sig_kernel_only(sig) \ 410 (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_ONLY_MASK)) 411 #define sig_kernel_coredump(sig) \ 412 (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_COREDUMP_MASK)) 413 #define sig_kernel_ignore(sig) \ 414 (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_IGNORE_MASK)) 415 #define sig_kernel_stop(sig) \ 416 (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_STOP_MASK)) 417 418 #define sig_user_defined(t, signr) \ 419 (((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) && \ 420 ((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_IGN)) 421 422 #define sig_fatal(t, signr) \ 423 (!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \ 424 (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL) 425 426 void signals_init(void); 427 428 int restore_altstack(const stack_t __user *); 429 int __save_altstack(stack_t __user *, unsigned long); 430 431 #define save_altstack_ex(uss, sp) do { \ 432 stack_t __user *__uss = uss; \ 433 struct task_struct *t = current; \ 434 put_user_ex((void __user *)t->sas_ss_sp, &__uss->ss_sp); \ 435 put_user_ex(sas_ss_flags(sp), &__uss->ss_flags); \ 436 put_user_ex(t->sas_ss_size, &__uss->ss_size); \ 437 } while (0); 438 439 #ifdef CONFIG_PROC_FS 440 struct seq_file; 441 extern void render_sigset_t(struct seq_file *, const char *, sigset_t *); 442 #endif 443 444 #endif /* _LINUX_SIGNAL_H */ 445